Pressure balanced expansion joints are a form of expansion joint used in piping systems that are designed to reduce the effects of pressure thrust on the piping system. They are typically used in locations where the pressure thrust of the system is too great to be supported by the pipe anchors alone. Pressure balanced expansion joints are designed to absorb the thrust forces while still allowing for thermal expansion and contraction of the piping system. They are also used to reduce vibration and noise in the system. Pressure balanced expansion joints are typically made of metal and rubber and are designed to be flexible to accommodate the changes in pressure, temperature, and movement of the system.